Process for rendering cellulosic textile materials transparent and products therefrom



Patented June 6, 1950 PROCESS FOR RENDERING CELLULOSIC TEXTILE MATERIALSTRANSPARENT AND PRODUCTS THEREFROM Ernst Weiss, Bunt, Wattwil,Switzerland, assignor to Heberlein Patent Corporation, New York, N. Y.,a corporation of New York No Drawing. Original application March 27,

1948, Serial No. 17,596. Divided and this application December 16, 1948,Serial No. 65,745. In Switzerland October 26, 1942 Claims.

This invention relates to a process for rendering textile materialstransparent and particularly to producing such transparent fabrics bythe use of special groups of synthetic resins employed with selectedfabrics under restricted conditions, as hereinafter set forth. Theinvention also relates to the products resulting from such process.

One object of the invention is to provide improved fabrics of this typewhich show an all-over effect or a pattern design. Other objects andadvantages will appear from the following description.

The invention accordingly comprises the novel products as well as thenovel processes and steps of processes according to which such productsare manufactured, the specific embodiments of which are describedhereinafter by way of example and in accordance with which I now preferto practice the invention.

This application is a continuation-in-part of my copending applicationsSerial No. 504,1l9 filed September 28, 1943, and Serial No. 578,567,filed February 17, 1945, both now abandoned, and is a division of mycopending application Serial No. 17,596, filed March 27, 1948, nowPatent No. 2,466,066. In said last mentioned application, the processfor rendering cellulosic textile materials transparent and productstherefrom, is claimed broadly, and is claimed specifically with regardto melamine formaldehyde ether resin, and with respect to certainaminoplast ether resins reacted with alkyd resins. In the presentapplication, the invention is claimed broadly and specifically withregard to urea, formaldehyde ether resins.

I have found in accordance with my invention that such transparentfabrics may be obtained by the use of cotton and artificial silk. withether resins selected from the group consisting of an aminoplast etherresin and an aminoplast ether resin reacted with an alkyd resin having afree hydroxyl group in which the ether radical other than that of thealkyd group contains no more than 7 carbon atoms.

The fabric employed is an open-meshed fabric selected from the groupconsisting of regenerated cellulose, as rayon and spun rayon fabric, andcotton fabric. Also silk, wool or fibres from superpolyamides orpolyurethanes known under the name of nylon and Perluran or Perlon aresuitable as starting materials. The fabric which I employ to give thetransparent effect is airor fluid-permeable and has 45 to 130 threadsper inch, the threads being No. 30 to No. 200 English count for cottonand spun rayon fabrics and 45 to 150 denier for rayon fabrics. Thefollowing fabrics have been satisfactorily employed in the carrying outof the invention: muslin, Geisha, voile, cretonne, crepe Georgette, andcrepe de Chine, which employ cotton, spun rayon and artificial silk ofregenerated cellulose. The number of threads per inch, as well as thekinds of threads, No. 30 to No. 200 English count for cotton and spunrayon fabrics and 45 to 150 denier for rayon fabrics, as aboveindicated, occur in the fabrics last-mentioned.

The resin is employed in the form of a. fluid composition which may beeither a solution or an emulsion which contains 10 to of ether resin.The ether resins which I employ are insoluble in water, but are solublein organic solvents. Specific resins which I have successfully employedinclude melamine formaldehyde ether resin, urea formaldehyde etherresin, alkyd amino triazine aldehyde mixed resin, and alkyd ureaformaldehyde mixed resin. The ether radicals in each of the above may beintroduced by condensation with alcohols containing from 1 to 7 carbonatoms, namely, by condensing with methyl, ethyl, propyl, butyl, amyl,hexyl or heptyl alcohols and also with polyvalent alcohols. I haveobtained particularly good results by the use of butyl alcohol.

After impregnating the fabric with resin, it is heated at an elevatedtemperature; whereupon, the resin sets and the fabric acquires atransparent condition and has a soft handle. The fabric in its completedtransparent condition contains about 15 to 45% by weight of said resinbased on the weight of the original fabric.

The fabrics made in accordance with my invention are distinguished fromthe so-called oil skins heretofore proposed and manufactured which aremade up of silk and other fabrics in closely woven condition with acontinuous air-impermeable coating of various kinds of resins in whichthe completed oil skin contains from 50% to 500% of resin coating basedon the weight of the fabric.

Open-meshed fabrics treated in accordance with my invention by applyingthe resins herein described to produce an all-over effect, result inopen-meshed and porous fabric, like organdy. Open-meshed fabrics locallyprinted with such resin compositions result also in fabric which isopen-meshed in the printed portions.

The production of this transparent or organdy effect, I believe to bedue to the fact that the regenerated cellulose and cotton fabricsemployed have substantially the same refractive indices as the etherresins (in dried condition) with which they are impregnated inaccordance with my invention.

Softeners may be employed in the resin solution or emulsion, such as,for instance, tricresyl phosphate, diethyl phthalate and similarproducts.

They may also be added prior to the impregnation or during theproduction of the synthetic resin precondensate. In applying the resinsas solutions, they are used ordinarily in organic solvents, forinstance, but without limitation, in liquid alcohols. These resins, asstated, are substantially insoluble in water. Instead of using them inorganic solvent solution, they may be employed as emulsions in waterwith suitable emulsifying agents.

when pattern effects are applied locally, the effectiveness of suchpatterns may be increased by combining same with pigment printing,pigment resists and, if desired, by subsequent local shrinking of thefabrics.

The impregnation is carried out, for instance, by the use of a foulardor padding machine, or by a coating knife. Interesting pattern-effectsare obtained by previous printing with a pigment resist. In case ofpatterns effected by direct local application, a sufliciently viscoussolution or emulsion is applied by roller printing or stencil printing,and preferably by adding to the solution or emulsion softeners andthickening agents.

After application, baking occurs preferably in the absence of catalystshaving an acid reaction.

The treated fibres possess the properties of having a highertransparency than the basic fiber material; having a content of aminoplast ether resins and a reduced tendency to curl and shrink uponwashing.

The following are examples of the manufacture and application totextiles of various ether resins. Resins A, B are representative ofunmixed resins, i. e., without the alkyd group, and Examples 1 to 17,inclusive, represent the application thereof to fabrics. amples are tothe production and application of the mixed resins, i. e., containingthe alkyd group. It is to be understood that these examples areillustrative of the invention and the invention is not to be consideredas limited thereby except as indicated in the appended claims.

EXAMPLES Pazrmnon or m Erma Rnsms (A) ResinP-Urea formaldehyde butylParaformaldehyde and hexamethylene tetramine are dissolved in hotN-butanol. After cooling, the urea is added and thereupon the solutionis brought slowly to the boiling point, then boiled for about 20 minutesunder a reflux condenser. Thereupon the formic acid is added. Thereaction water formed upon further heating and part of the butanol aredistilled off. The mixture of butanol and water found in the distillateis separated; the butanol is returned to the reaction mixture while thequantity of reaction water obtained is continuously checked. Thedistillation is continued until about 2 mols of reaction water haveseparated-which when using the above quantitative ratios, is 144 gramsof water. The result is a viscous stable solution of urea formal- Theremaining ex-- 4 dehyde butyl ether resin in butanol, containing aboutof resin.

(B) Resin-Melamine formaldehyde butyl ether resin One thousand grams ofhexamethylol melamine are added to 3,000 grams of N-butanol while usinga reflux condenser. Thereupon, cc. of concentrated formic acidcontaining 120 grams of formic acid are added and the reaction waterobtained and a part of the excess butanol are slowly distilled off. Thedistillation is advisedly continued until 2,000 grams of distillate havepassed over. The solution obtained then contains about 80% of melamineformaldehyde butyl ether resin.

(C) Fifty grams of boiling water are poured over 2.5 grams of methylcellulose and stirred, under refrigeration, until completely dissolved,then 100 grams of water saturated with butanol is stirred in; then 3grams of dimethyl benzyl lauryl ammonium chloride dissolved in 9 gramsof ethyl alcohol (30%) are stirred in; thereupon 100 grams of A Resinsolution, prepared according to the example above, and diluted withbutanol to a. resin content of 60% is added while vigorously stirring.The result is a 23% emulsion of urea formaldehyde butyl ether resin inwater.

(D) One gram of polyvinyl alcohol is dissolved in 60 grams of water;then 30 grams of 5% aqueous solution of methyl cellulose and 9 grams ofbutanol are added; thereafter 100 grams of melamine formaldehyde butylether resin (70%) B Resin solution, prepared according to the exampleabove, is added while vigorously stirring. The result is a 35% emulsionin water of melamine formaldehyde butyl ether resin.

Resin solutions and emulsions of Resins A and B are solutions oremulsions of unset resins which are set by heating to the temperatureslfOl baking given in the examples.

The viscosities of the resin solutions as employed in accordance withthe invention may vary through wide limits, since all solutions whichmay be applied satisfactorily and which will impregnate the fabric areusable. Heating of the solution will lower the viscosity and,accordingly, some solutions which may be applied with dimculty can beused since upon heating as indicated in the examples below, suflicientpenetration to impregnate the fabric will occur. The viscosity of theresin solutions as applied may accordingly range from 100 to 10,000centipoises.

EXALLPLES APPLICATION 01 SOLUTIONS AND EIULSIONS TO FABRIC 1. A muslinfabric consisting of viscose rayon both in the warp and in the filler,with a titer of 60-75 deniers and having 84 x '72 threads per inch, issubjected to a preliminary cleaning in accordance with known methods anddried under tension. Thereupon the fabric is thinly coated on aspreading machine directly with the resin solution in butanol obtainedin accordance with A Resin; thereupon dried at about 60 C. andsubsequently heated for 15 minutes at C. There is thus obtained anexceptionally transparent fabric which is only slightly stiffened. Thefabric contains about 40% resin based on the weight of the originalfabric.

2. A colored muslin fabric of viscose rayon having 84 x 72 threads perinch is impregnated on a two-roller padder with the following mixtureand then squeezed:

Grams Resin solution made in accordance with Resin A 800 Tricresylphosphate 100 Ethyl alcohol 100 threads per inch is desized inaccordance with the known methods, bleached and thereupon dried undersharp tensioning in the direction of the warp and of the filler.Thereupon the resin solution produced in accordance with A Resin isprinted on. If the printing should not turn out sharply, i. e., if itshould show a tendency to run, it is advisabie to thicken the printingmass, for instance by theaddition of nitrocellulose. In accordance withthe following instructions, one obtains, on most fabrics, sharp clearprints:

Grams Resin solution made in accordance 'with Resin A 700 Nitrocelluloseof medium viscosity wetted with butanol 100 Amylacetate 200 Afterprinting, the fabric is subjected to a preliminary drying at 40-50 C.and then heated for minutes at 120 C. The unprinted portions orbackground are again creped by treatment in a 40-50 C. bath containing23 grams of soap or- 1 gram of Igepon T/L. The goods are thereuponrinsed and dried under slight tension. In this manner one obtainstransparent, smooth to slightly undulated, printed effects on a crepebackground.

4. A fabric made from cuprammonium rayon, the warp of which consists ofcrepe yarns and the filling of ordinary yarns having 105 x 65 threadsper inch, is creped, boiled and dyed in accordance with the customarymethods. Thereupon the following mass is printed on:

Grams Resin solution made in accordance with Resin A 700Diethylphthalate Nitrocellulose of medium viscosity containing 35% ethylalcohol 80 Ethyl aceta 200 The printed fabric is predried at 50-60 C.andthen heated for 30 minutes at 100 C. In this manner one obtainstransparent printed effects; the contrast between the printed andunprinted portions being much increased by a considerable deepening ofthe color in the printed parts.

5. Bleached viscose staple fiber muslin having 87 x 80 threads per inchis printed with the mass mentioned in Example 4. It is then subjected toa predrying at 50-60 C. and then heated for 5 minutes at 140 C.Thereupon the fabric is dyed with substantive dyes. The dyeing on apadder in this connection proves to be exceptionally favorable. Onaccount of the resist effect of the resin mass, the printed parts arenot dyed at all or only slightly. In this manner, one obtains white orslightly colored transparent printed effects on a colored, opaquebackground.

6. The resin solution obtained in accordance with Resin A is printed onmercerized cotton muslin having 84 x 68 threads per inch, dried and thenheated for 5 minutes at 140 C. Thereafter the printed fabric is placedin caustic soda solution of 30 Be. for 4 minutes; whereupon, andpreferably after-drawing or suctioning off the excess lye, the remaininglye is removed with hot water, andthe fabric is then acidified andwashed until neutral. Finally the fabric is dried under slight tension.Depending on the selection of the pattern, one obtained more or lessstrongly undulated comparatively soft transparent patterns on a shrunkenbackground.

7. Mercerized cotton muslin having 87 x threads per inch is printed withthe resin solution obtained in accordance with Resin A. If the printingmass should have a tendency to run, then it can be further thickened byan addition of a small quantity of nitrocellulose plus amylacetate.After the printing, the goods are subjected for a short time topredrying and thereupon heated for 5 minutes at 140 C. The fabric isthereupon again printed but with the use of 1:1 gum arabic solution.Interesting effects are obtained if one uses for the printing with theresin mass a fancy design with irregularly distributed areas and lineswhile for the printing over with gum arabic one uses a simple stripedesign. After the printing over, the goods are dried, treated with 30 B.caustic soda as described in Example 6, and after the excess\ lye isremoved, the goods are acidified, washed until neutral and thereupondried with as little tension as possible. The resulting fabric showstransparent and, in accordance with the design, smooth to slightlyundulated printed parts on an undulated crepe-like background.

8. Viscose marquisette having 60 x 66 threads per inch is impregnatedwith a solution of the following composition and thereupon stronglysqueezed:

Resin mass produced in accordance with Resin B (containing about 80% ofthe Thereupon the goods are subjected to predrying at increasedtemperature and then heated for 5 minutes at 140 C. The fabric in thisway is made transparent to a far-reaching degree without being stiffenedto a disadvantageous extent. The fabric contains about 30% resin basedon the weight of the original fabric. 7

9. Bleached viscose muslin having 87 x 80 threads per inch, colorprinted in accordance with the customary fabric printing methods, isthinly coated with an approximately 70% of resin mass produced inaccordance with Resin B and thereupon heated for V hour at C. Oneobtains in this way a beautiful clear transparent fabric with coloredprinting effects. The resin content based on the weight of the untreatedfabric is about 40%.

10. Crepe Georgette consisting of viscose crepe yarn both in the warpand in the filler having 91 x 84 threads per inch, is scoured andbleached in accordance with the known methods. Thereupon it is subjectedto a preliminary tentering with strong tensioning in the direction ofthe warp as well as in the direction of the filler and printed with:

Grams Resin mass produced in accordance with Resin B (containing about80% 'of the melamine formaldehyde butyl ether resin)--- 700Nitrocellulose of medium viscosity, wetted with butanol 100 Amylacetate200 After drying, heat for minutes at 140 C. The fabric is then placedin a dye bath preheated to about 50 C. and dyed preferably with the useof substantive colors in order to obtain the desired shade. Thereby thebackground is creped while the printed places remain smooth or areslightly undulated. The printed places are not colored or only veryslightly. Finally the fabric is dried with the least possibletensioning. The results are white or slightly colored, smooth orslightly undulated transparent printed parts on a colored crepebackground.

11. Mercerized bleached cotton voile having 60 x 53 threads per inch isprinted with the mass described in Example 10, dried and heated forminutes at 130 C. Thereupon the fabric is printed over with thickenedcaustic soda solution of 40 B. preferably in the form of a stripedesign, then set aside for some time, namely, until the desiredcontraction of the printed places has occurred and thereupon the lye isremoved with hot water, and the goods are acidified and washed. Finallythe goods are dried with the least possible tension. One obtains in thisway transparent printing effects on a crepe-like undulated background.

12. Bleached viscose muslin having 8'7 x 80 threads per inch is printedwith a pigment resist of the following composition:

After the drying out of the printed parts, the fabric is thinly coatedas described in Example 1 with the resin solution obtained in accordancewith Resin A, then subjected to a preliminary drying and thereuponheated for minutes at 110 C. The fabric now shows striking white opaqueprint effects on a transparent background. It has stiffenedcomparatively little. The fabric contains about 40% resin based on theweight of the original fabric.

13. Mercerized bleached cotton muslin having 84 x 68 threads per inch isprinted in one printing process with the use of two design rollers whichare in registration with each other; one roller prints with the pigmentresist of Example 12 and the other roller prints directly on top of thefirst print with Resin B, thickened with nitrocellulose (as per Example10). Now the fabric is heated for 15 minutes at 140 C. and thereuponshrunk by placing in 30 Be. caustic soda. After the removal of the lye,acidification and washing, the goods are dried with the least possibletension. In this way one obtains very striking white printed effects ontransparent and only slightly stiflened lightly undulated design partswhich are surrounded by a dense muslin back round.

- dried with the least possible tensioning. The

fabric has now been given slightly stiffened transparent design partswith white opaque printing effects in same and alongside of sameunchanged and shrunken fabric parts.

15. A muslin made up of cotton warp and viscose filling having 91 x '76threads to the inch is impregnated on a padder with emulsion designatedas (C) above. The material is then dried at about 50 to C. andsubsequently heated for ten minutes at 120 C. There is thus obtained atransparent fabric. The fabric contains about 20% resin based on theweight of the original fabric.

16. A cotton and viscose muslin as in Example 15 is impregnated on a tworoller padder with resin emulsion designated as (D). The material afterpredrying at 50-60 C. is then baked during four minutes at 140 C. Thefabric produced is transparent and only slightly stiffened. The fabriccontains about 30% resin based on the weight of the original fabric.

17. Viscose rayon marquisette, having 60 x 66 threads per inch, isimpregnated on a two roller padder with a diluted resin emulsion; to onepart of resin emulsion designated as (D), two parts of water are stirredin. The fabric is then dried at about 50 to 60 C. and subsequentlyheated for 6 minutes at 130 C. There is then produced a translucentfabric well suited as curtain material. The resin content of the sotreated material is about 15%.

18. A dyed muslin fabric which is an openmeshed fabric, the warp andfilling consisting of viscose rayon, having 84 x 72 threads per inch, isimpregnated on a coating machine with a solution of an alkyd aminoplastether resin, namely, an alkyd-amino-triazine-aldehyde mixed resin inbutanol, containing 60% dry residue, and subjected to a preliminarydrying at about 60-70 C. Thereupon the fabric is heated for 15 minutesat 120 C. In this way there is obtained an all-over effect, viz., apronounced transparent fabric which has an open mesh and which is onlyslightly stiffened comparatively. The fabric contains about 40% resinbased on the weight of the original fabric.

A suitable mixed resin is obtained in the following manner: 92 parts ofglycerin are esterifled with 71 parts of stearic acid by! heating to220-240 C. up to an acid number of 6. Thereupon esterification iscontinued with 148 parts of phthalic anhydride up to an acid number of42. In order to etherify the remaining hydroxyl groups of the glycerin,the alkyd resin thus obtained is boiled under reflux with 102 parts ofhexamethylol melamine, dissolved in 222 parts of butanol, for 1 /2hours. Thereupon the solvent is distilled off until a resin solution inbutanol is obtained.

19. Bleached viscose staple fibre muslin, an open-meshed fabric, having87 x threads per inch, is printed with a mass of the followingcomposition:

Grams 80% solution of an oleic acid modifiedalkydamino-triazine-aldehyde mixed resin in butanol 800 Nitrocelluloseof medium viscosity, moistened with 35% butanol 20 Amylacetate 180 Afterthe printing, preliminary drying is effected at 60-70 C. and thereuponthe mass is heated for minutes at 130 C. Now the goods are dyed with theuse of substantive dyestufls.

- thiophenols are known under the names of Katanol W, Thiotane'RS, etc.

The above oleic acid modified resin can, for instance, be prepared asfollows: 92 parts of glycerin are esterified with 141 parts of oleicacid and 148 parts of phthalic anhydride by heating for several hours at220-240" 0. up to an acid number of 30. The resin thus obtained isdissolved in 222 parts of butanol, and 102 parts of hexamethylolmelamine are dissolved therein by heating. The solution is then heatedfor 4 hours at 100 C., whereupon enough butanol is distilled off so thatan 80% resin solution in butanol is obtained.

20. Crepe Georgette viscose rayon, an openmeshed fabric having 91 x 84threads per inch, is desized in accordance with the known methods,bleached, and then dried under sharp tensioning in the direction of thewarp and filling. Then the fabric is printed with the resin as describedin Example 19, subjected to preliminary drying, and thereupon heated for4 minutes at 140 C. By treating in a 30-40 0. bath, containing 2-3 gramsof soap or /2 to 1 gram of an aliphatic alcohol sulfonate or V2 to 1gram of a fatty acid condensation product such as Igepon per liter, theunprinted background is again creped. In many cases, insertion of thegoods in 30-40 C. water sumces to effect this subsequent creping. Afterthis creping treatment, the goods are rinsed, if necessary, whereuponthey are dried under slight tensioning. In this way there are obtainedtransparent, smooth to slightly wavy, printed eflects on a typical crepebackground.

21. An open-meshed fabric produced from cuprammonium rayon, the warp ofwhich consists of crepe yarn and the filling of which consists ofordinary yarn, having 105 x 65 threads per inch, is creped in accordancewith the customary methods, soaped and dyed, for instance, light blue,with a substantive dyestuif. The goods are thereupon dried whilestretching same well in the direction of the warp and of the filling.The goods are thereupon printed with the printing mass described inExample 19, subjected to a preliminary drying at 60 to 70 0., heated for30 minutes at 110 C., subjected to recreping by placing in water of 300., and dried while under 10 slight tension. Depending on' the intendedpurpose, the fabric can be finished and calendered in accordance withthe customary methods. One obtains in this way transparent printingeflects on an opaque background. The contrast between the printed partsand the background is further essentially increased by a considerableintensifying of the colors in,t he printed parts.

The transparent prints can aEo be combined with ordinary color prints,in connection with which it is possible to print, for instance, vatdyes, in one printing process simultaneously with transparent printingmasses.

22. A spun rayon cretonne, having 70 x 70 threads per inch, is printedwith a mass which essentially consists of mixed alkyd-urea-aldehyderesin which is, an alkyd aminoplast ether resin. Such a mixed resin canbe produced as follows: 92 parts of glycerin are esterified with '71parts of stearic acid by heating at 220-240 0. up to an acid number of6. Thereupon the esterification is continued with 148 parts of phthalicanhydride up to an acid number of 42. The alkyd resin thus obtained isnow dissolved in 222 parts of butanol and parts oi' dimethylol urea areadded. The mixture is boiled for 2 hours under reflux and thereupon sucha quantity of solvent is distilled oil that an 80% resin solution inbutanol results. The printing mass produced from this resin solution hasthe following composition: I

Grams Alkyd-urea-formaldehyde mixed resin 80% 750 Tricresyl phosphate 60Nitrocellulose of medium viscosity moistened with 35% ethyl alcohol 20Amy] acetate 50 Ethyl acetate 50 Toluol '10 After the printing, Dre-dryat '10 to 80 C. and thereupon heat for 3 minutes at 150 C. Thereupon thegoods are advisedly finished with one of the softening agents generallyknown in finishing practice; then dried under tension and calendered.The fabric now shows comparatively soft transparent printing effects onan opaque and lustrous background. Depending on the incidence'of thelight, the prints obtained in this manner remind one of marked damaskeffects.

23. A mixed resin produced in accordance with Example 18, is adjusted,by the addition of amyl acetate, to a resin content of 65% and thereuponprinted on mercerized cotton muslin, an openmeshed fabric, having 84/68threads per inch. Should the print be inclined to run, then the resinsolution can be thickened by the addition of small quantities ofnitrocellulose. After printing, subject the goods to a short preliminarydrying and then heat for 5 minutes at C. Now the printed fabric isplaced for 4 minutes in a caustic soda solution of 30 B., whereupon,advisedly after previous drawing oil by suction of the excess causticsoda lye, the lye is removed from the goods with warm water andthereupon the fabrics are washed in running water until the completeremoval of the alkali. Finally the goods are dried under slight tension.Depending on the selection of the pattern, one obtains more or lessstrongly undulated and comparatively soft transparent patterns on ashrunken background.

With respect to the fabrics produced by printing in the above examples,such printed fabrics in the printed portions contain about 20 to 45% byweight of resin based on the weight of the original fabric.

Each of the fabrics employed in accordance with the above examples iswithin the range of 45 to 130 threads per inch of threads of No. 30 toNo. 200 English count for cotton and spun rayon fabrics and from 45 to150 denier for rayon fabrics.

The resin solutions in Examples 18 to 23 are solutions of unset resinswhich are set on baking.

The making of such compounds, as, for instance, alkyd amino triazinealdehyde mixed resin is described in French Patent No. 867,065;analogous compounds with urea are described in British Patent No.344,401.

An advantage of, the process in accordance with my invention consists,for example, in that the synthetic resins used dry better and morerapid- 1y than previously known materials. There is furthermore obtainedan excellent transparent effect and an improved fastness to washing.

Special effects can be obtained, as explained in Example 19, if one dyesthe fabric subsequently with substantive dyes, possibly with theaddition of thiophenols which have been made soluble. Crepe fabrics, forprinting with transparent patterns, are strongly stretched along thewarp and along the filling, if necessary and are also dried in thiscondition and thereupon again creped, for instance, in a soap bath.

Unique or special effects can be obtained also if one dyes the fabricsbefore the placing on of the transparent patterns as stated, forinstance, in Example 21. One obtains in this way, at the transparentplaces, a strong intensification of the dyeing. Similar effects can beobtained if one prints the fabrics with color patterns and if oneapplies simultaneously, alongside of same or over same, transparentpatterns.

A further enrichment of the effects obtained by this process can beachieved by combination with pigment printing. Exceptionally interestingeffects are obtained if one prints, in one printing operation, usingdifferently adjusted printing rollers, first a pigment resist and on topof it a lacquer printing mass of, for instance, the kind described inExamples 19 or 22. One can produce in this manner attractive white orcolored opaque pigment printing effects, in transparent, very littlestiffened, pattern portions which, in turn, are surrounded by theunchanged or, if desired, shrunken fabrics. Such pigment prints can alsobe made preceding a single or plain allover transparentizing inaccordance with Example 18; one obtains then attractive opaque printingeffects on a transparent open-mesh background. As binding agent for thepigment printing masses there can be used the customary binding agents,for instance, solutions of cellulose esters, but also solutions of thealkyd-aminoplast ether resin mixtures described in the foregoingexamples.

By dyeing the resin masses, for which purpose among others the so-calledalcohol soluble dyestuffs are very suitable, for instance, Sudan red,there are available a number of further variants especially for theproduction of printed effects. Interesting effects can also be obtainedin the manner that after the printing or the resin masses on thecellulose fabric the dyeing is done with acid dyestuffs in connectionwith which only the printed places are deeply colored while theunprinted fabric parts are not colored at all or only slightly. If thedyeing is done in a bath which contains at the same time acid andsubstantive colors, one obtains the most varied twocolor eil'ects.depending on the dyestui! used.

While the invention has been described in detail according to certainpreferred methods of carrying out the process, it will be obvious tothose skilled in the art after understanding the invention,that changesand modifications may be made therein without departing from the spiritor scope of the invention, and it is intended in the appended claims tocover all such changes and modifications.

WhatIclaim is:

1. A process for transparentizing textiles which comprises, impregnatingan open-meshed fabric with an unmixed water-insoluble urea formaldehydeether resin, said fabric being woven from thread selected from the groupconsisting of continuous filamentary rayon, spun rayon, and cotton, eachof said rayons being of regenerated cellulose, said fabric having 45 to130 threads per inch in warp and weft, said threads being No. 30 to No.200 English number for cotton and spun rayon fabrics and 45 to 150denier for continuous filamentary rayon fabrics, said ether resin beingemployed as a fluid composition containing 10 to of said ether resin,the ether radical of said urea formaldehyde ether resin containing nomore than 7 carbon atoms, and heating to render the impregnated materialtransparent, said material in completed transparentized condition havingabout 15 to 45% by weight of said resin based on the weight of theoriginal fabric.

2. A process in accordance with claim 1, in which the resin is anunmixed urea formaldehyde butyl ether resin.

3. A process for printing fabric to produce a transparent design inaccordance with claim 1, in which the fabric is impregnated with anunmixed urea formaldehyde ether resin in the form of a design.

' 4. A transparentized textile fabric in which the fabric is woven fromthread selected from the group consisting of continuous filamentaryrayon, spun'rayon, and cotton, each of said rayons being of regeneratedcellulose, said fabric having 45 to threads per inch in warp and weft,said threads being No. 30 to No. 200 English number for cotton and spunrayon fabrics and 45 to denier for continuous filamentary rayon fabrics,said fabric being transparentized b an unmixed urea formaldehyde etherresin in which the ether radical contains no more than 7 carbon atoms,said fabric after transparentizing treatment, having fluid permeableinterstices.

5. A textile fabric in accordance with claim 4, having a patternedtransparent effect.

ERNST WEISS.

REFERENCES CITED UNITED STATES PATENTS Number Name 2,466,068 Weiss DateApr. 5, 1949

1. A PROCESS FOR TRANSPARENTIZING TEXTILES WHICH COMPRISES, IMPREGNATINGAN OPEN-MESHED FABRIC WITH AN UNMIXED WATER-INSOLUBLE UREA FORMALDEHYDEETHER RESIN, SAID FABRIC BEING WOVEN FROM THREAD SELECTED FROM THE GROUPCONSISTING OF CONTINUOUS FILAMENTARY RAYON, SPUN RAYON, AND COTTON, EACHOF SAID RAYONS BEING OF REGENERATED CELLULOSE, SAID FABRIC HABING 45 TO130 THREADS PER INCH IN WARP AND WEFT, SAID THREADS BEING NO. 30 TO NO.200 ENGLISH NUMBER FOR COTTON AND SPUN RAYON FABRICS AND 45 TO 150DENIER FOR CONTINUOUS FLIAMENTARY RAYON FABRICS, SAID ETHER RESIN BEINGEMPLOYED AS A FLUID COMPOSITION CONTAINING 10 TO 80% OF SAID ETHERRESIN, THE ETHER RADICAL OF SAID UREA FORMALDEHYDE ETHER RESINCONTAINING NO MORE THAN 7 CARBON ATOMS, AND HEATING TO RENDER THEIMPREGNATED MATERIAL TRANSPARENT, SAID MATERIAL IN COMPLETEDTRANSPARENTIZED CONDITION HAVING ABOUT 17 TO 45% BY WEIGHT OF SAID RESINBASED ON THE WEIGHT OF THE ORIGINAL FABRIC.
 3. A PROCESS FOR PRINTINGFABRIC TO PRODUCE A TRANSPARENT DESIGN IN ACCORDANCE WITH CLAIM 1, INWHICH THE FABRIC IS IMPREGNATED WITH AN UNMIXED UREA FORMALDEHYDE ETHERRESIN IN THE FORM OF A DESIGN.